Download presentation
Presentation is loading. Please wait.
Published byWinifred Anis Casey Modified over 8 years ago
1
CompSci 6 Introduction to Computer Science November 8, 2011 Prof. Rodger
2
Announcements No reading or RQ Assignment 5 due Thursday New APT out Thursday – one APT Practice Test problems out – will go over on Tues. Nov 15 Prof. Rodger no office hours this week Today –Finish example from last time –More on sort options –Regular Expressions
3
More on sort Import operator –fruit = [(“pear”,5),(“apple”,9)] fruit = sorted(fruit) fruit.sort() OR fruit = sorted(fruit) –arguments key=itemgetter(0) reverse=True
4
Regular Expressions Part of the compiler process –Can write a regular expression for each type of word in a programming language –Example Key words – if, else, elif, while Integers – 456, 78, 2, -56 Float – 3.14, 7856.2345 String – ‘word’, “this is a phrase” Special symbols – [ ] + %
5
Regular Expressions a- a a* - a repeated 0 or more times a+ - a repeated 1 or more times a? – a 0 or 1 time, so a is optional ^ - match at the beginning of the string $ - match at the end of the string. – matches anything [abc] – match a, b, or c [a-z] – match any character from a to z [^a] – match any character but a
6
More on regular expressions | - or \b - word boundary \s - whitespace character \d – match any digit When using backslashes – must use r in front of string
7
Regular expressions with re import re re.sub() – substitute re.compile() – create a pattern re.findall() See examples
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.